Typewriting machine



Oct. 1 7, 1933. w. ETTMULLER 1,931,067

TYPEWRITING MACFIINE Filed June 21, 1932 Flf'l.

/ f @0l/r f//f n/ v inch in diameter;

CII

Patented Oct. 17, 1933 y UNITED STATES Y TYPWRI'TING MACHINE Walter Ettmiiller, Zurich, Switzerland, assignor to Underwood Elliott Fisher V`Company, New

' York, N. Y., a corporation of Delaware Application June 21, 1932. serial iaaisficzA 7 claims. (o1. 197-123) This invention relates toplaten-release mechanisms of typewriting machines.

release mechanism for portable typewriters that is easily operated, one that is positive in locking the platen and line-space wheel securely together, one that may be applied with minimum changes to the platen-structure as used where no releasev mechanism is employed and applied in'such a wayV that the platen may be readily slipped into and out of the carriage.

The usual carrying case is placed over the entire typewriter, thereby limiting the` length of the typewriter-carriage, and precluding the regular application of the well-known platen-release devices, since these extend the overall length of the carriage considerably. 4 i, 'l

In the Underwood portable typewriter, the linespace wheel is located-,close to one end of `the platen within the space between said platen and the side member of the platen-frame. The platen itself is of limited length (9 inches), and, for compactness, the platen-frame side members are close to the ends of the platen. 1

It is not feasible, on account of the closeness of the platen-frame side member, and the adopted,

organization of-the line-space lever andpawl devices, to move the line-space wheel outwardly, to

sible to reduce the length 'of the platen to afford such room, because thiswould correspondingly reduce the width of work-sheet which may beV used.

Certain platen-release mechanisms heretofore evolved, are incorporated withinthe platen itself, and not only take up considerable room lengthwise of the platen, but require considerable modii'lcation of the platen-structure, as compared with` the regular structure when no platen-release mechanism is used. The platen of the Under-y wood portable typewriter is about 11/4 inches in diameter, the core of the platen being about 1 A release-mechanism incorporated within the platen must be within' the compass ofthe rcore-diameter. If, through the use of long clutch-actuating levers extending in the direction of the platen-axis, such mechanism extends considerably into the platen, it will be seen that difficulties of construction and assembly are entailed on account of the` small compass of the core-diameter. It is important that the clutchvbe positive, that is, it must lock the. platen and line-space wheel together securely, so that there may be no relative rotation between the two;

An object ofl the invention is to provide a suiciently compact tuatedv bytoggle-leverjv devices, all Within .the l Furthermore, the clutching and unclutching opv eration must be done with celerity, and` must;Y therefore, be effected with little effort of the operators fingers. w

.A clutchl that, in'respect to positive gripping 60 f and ease of actuation, is very efcient, is seen in the patent to Helmond, No. 1,150,366, datedAu- Y gust 17, 1915. In the Helmond device, the clutchproper comprises an annular bearing "surface gripped by arcuate` clutch-members forcibly exv panded against said surface by toggle-lever devices.V In theHelmond organization, the entire clutch-mechanism is outside of the platen-frame. and its connection with the' platen is through the platen-knob, which is secured to the platen-shaft.-

ganization applicable to a Vportable typewriter, i

and it -is contrived to work into said new organi-` zation, as clutch-elements,` an annular bearing., g surface gripped by arcuate clutch members ac-v limited compass'of the -portable typewriter-platen 0' and its carriage'. A portable typewriter-platen of regular length is used. The line-space wheelV is maintained in its regular position,thus vobviating the necessityof changing the regular liner,l space lever and pawl organization. s Within the platen-end .adjacent toA the line-n spacewheel, a shallow shell is sunkp and' may-be secured-to the platen-core by ,screwsgfsaid shell v having preferably an inner lwall or bottom which` abutsthe end of said core. Against the internal 90 periphery of the shell arcuategrippingmembers keyed to theline-space Wheel are forced to clutch said shell by toggle-lever devices. Such a.l clutch 'g is by reason of the principle of thejtoggle-,leverl devices and the peripheral gripping, very'efflcientv in locking vthe platen and line-spacefwheel together, and is also4V easily operated togrip or let go, the clutching and releasing operation requiring little effort of the operators fingers, notwithj standing the security with which the clutch holds. A plain platen-shaft of the small diameter requisite for free `rotation may be used, and -1 to this shaft thev platen is keyed by means `of a set- Y screw threaded through the usual hub-1in vthe opposite end of the platen and seated againstv a flattened portion of theshaft;4 The platenshaft is continuous, that is, it is in one pieceex` tending through and beyond the ends of the: platen, so that it may be journaled in the end members `of, the platen-frame.v and so that it `the platen and line-space wheel-together. engaging the detent-grooves in the pins, springprojects beyond said end members, to carry at one end the usual nger-knob, whereby the platen may be rotated, and, at the other end, a knob slidable axially of the shaft. Both knobs are outside of the platen-frame, that is, they are, for easy manipulation, beyond the end members thereof. By means of a thimble-cam projecting through a central opening of the line-space wheel, and slidable axially of the platen-shaft, the toggle-levers of the clutch may be spread to lock the line-space wheel and platenrtogether, such spreading occurring when the thiinble-cam is 4 vslid toward the clutch. When the thimble-cam is slid in the opposite direction, the toggle-levers automatically relax and the platen is free tonbe rotated independently of thefline-space Wheel. For connecting the slidable nger-knobon the outside of the platen-frame'to the thirnble-cam which is within theplaten-frame, a pair of pins, on diametrically opposite sides of the shaft, pass through the platen-frame end member which is between the slidable finger-knob and the thimble-cam. Said pinsv are joined at one end to said slidable knob, and, at their other ends, which are within the platen-frame, said pins are articulated with the thimble-cam in a manner to permitfree rotation of said cam when .said cam is entered between and therefore interlocked with the toggle-levers for the clutch. The pins may have detent-grooves engageable by spring-A pressedSdetent-devices when the thinible-cam is, by means of saidpins" and the slidable fingerknob at'the'end thereof, pushed in for locking For pressed plungers may be used, and are retained ina suitable housing, which may be secured to the side .of the platen-frame end memben-'and v through which housing the thimble-carn en- 40'! gaging pins mayy also pass.

AThe vtoggle-levers and co-operating arcuatev clutching v.members are keyed to the line-space wheel by'means of a loose disk disposed within I the shell that-is sunk into the end of the platen- ,l its attached clutch-membersrfrom creeping -wardly from said edge of the shell'.

-'frame,rsaid disk abutting the inner wall or end of` said shell." For maintenance in .true position the disk mayhave al fairly long hub rotatably tting the platen-shaft and extending within'.

the platen-core. A similar hub, extending with- I'in the platen-core from the aforesaid shell which.

is securedtosaid core, may rotatably t said diskhub, to thereby rotatably support the vclutch-end- Vof the platen concentric ywith the platen-shaft. The disk has studs projecting outwardly toward the end of the platen, so that thel line-space wheel, which is 'in the form of a at'notched disk, maybe attached thereto,v as by screws threaded into said studs. that when the disk abuts the bottom of the shell,

lthe inner face of the line-space wheel is'just free of theouter rim or edge of the shell.V A suitable abutment may project inwardly from the platenframe end to prevent the "line-space wheel and.

out-

'In'V thenew organization, the platen-assembly includes thev platen-proper andits'core with the regular Ahubfasten'ed to-one end, the other end Ahaving'the aforesaid shell, the line-space wheel ,the platen is mounted in the carriage. platen thus has the same flat end formed bythe forming a'cover for said shell and itscontained The studs are. of Asuch length line-space wheel as in the regular Underwood portable typewriter-platen. That is to say, there are no projections, protuberances, or other features of the organization to impede slipping the platen into and out of the platen-frame. If, with the platen in place within the frame, it is desired to withdraw the platen, all that is necessary is to loosen the set-screw in the aforesaid regular hub at one end of the platen, whereupon thel platen-shaft, with its attached iinger-knob, may

`be Yfully withdrawn. The central opening of the line-space wheel which surrounds the thimblecam may be sufciently large, so that when the platen is slightly cocked'after withdrawing the shaft, it may be readily `withdrawn from the platen-frame completely. The thimble-cam may also be articulated with its operating pins in suchA a way that'when the platen-shaft on which said thimble-cam is sldably supported is withdrawn, said cam is capable of a floating movementabout itsl connections with said pins, which conduces to the ease with .which the platen may be completely withdrawn. Y

' Other features and advantages will hereinaftery a appear.

InY the accompanying drawing,

`figure 1 is a longitudinal View of the platen in to expand-the clutch-members. v

Figure 5 is a perspective-view of the vassembledv platen-release mechanism, certain `parts being shown-in section to illustrate the novel organization. l

Figure `6 is a View illustratinghow the thimblecam may be snapped overv the operating pins whichproject throughthe side lof the platenframe. f Y y v i f Figure 7 isfa perspective View showingthe parts of the platen-release organization spread out to bring out details of saidparts.

Figure 8 is a detail View oiv a block for hous-'I ing detent-devices for the'thimble-cam.

The platen-frame of the Underwood portable typewriter includes a leftend member 10 and a right end member 11 in which there is journaled a platen-axle 12. A' cylindrical platen 13 has a core '14, to the right end of which is secured, in' the usual manner, a iianged hub 15.v By means of a set-'screw 16, threaded into said hub land tightened against a ilattened portion 17 of the? platen-shaft 12, the assembled 'platen iskeyed to the platen-shaft.

platen in which'there is received a shell 19,` said v shell having a long hub 20, tting an enlargement'of the central opening of the core 14, and also having'an inner wall 21 through which pass screws 22 fer fastening said shell 19 to said core. The shell 19 is of the same outer diameter as the core 14 to forni a continuous cylindrical surface with the latter upon which vthe platen-proper is The lright endof said shaft 12 carries the usual finger-knob 18 for rotating lieved as at 27,so that the disk .25 bears only against an outer rim of said wall. ProjectingV from the disk 25.is a pair of diametrically opposite studs 28, to which the line-space wheel 24 is secured by screws 29, whose heads are counter-` sunk below the outer surface of said-line-space,`

Wheel. Of the driven and driving members of the clutch-mechanism, the shell 19 keyed to the platen 13 forms one member and the line-space wheel 24 keyed to the disk 25 forms anothery member. For releasably connecting the two members, there is Within the clutch `a pair'of arcuate members 30, one end of each of which abuts a block 31 projecting from the diskv 25 and fastened thereto by dowels 32. From the block 31 the clutch-members 30 extend circumferentially around the inner' surface. of the shell to an extent which affords, between the other ends of said arcuate members 30, a space in which there 5 playsv a toggle formed by arms 33 of a pair of levers 34, as seen in"Figures 2 and 3. `The middle joint of said toggle is formed by a floating pin 35 that is articulated with conforming recesses in theinner opposite ends. of the togglearms 33. The outer endsof the toggle-arms`33 are similarly articulated with the respective ends of the arcuate members 30 by pins 37, these latter pins also floating. It will be seen from Figure 3 that with the arcuate members 30 reacting at one end against the block 31, and with the toggle-arms 33 almost'y straightened out, the.`

clutch-members 30 will be powerfully 4 forced against the annular surface .of the shell 19 and' the platen and line-space wheel will therefore be securely locked together. Conversely, if the toggle is relaxed or broken as inFigure 2,` the clutch-members 30 will not grip the annular surface of the shell 19 and the Vplaten may then be rotated independently vof the lline-space wheek For straightening and breaking the toggle formed vby the arms 33, the levers 34 have arms 36 which the disk 25, there is provided -a disk 39 having openings 4() to fit over the studs 28. To clear the inner surface `ci? the -shell 19, said disk is of a somewhat smaller 4diameter, `than said surface. Said disk also `has a deep notch 41, sothat when it is in place, it clears the .block 31 and also a thimble-cam 42. For holding the. disk 39 in position to retain the clutch-parts, it may be spaced from the line-space wheel 24 in any suitable manner, as, for example, by sleeves or springs 434 (Figure 7) surrounding the studs 28-one end of said springs abutting the line-space wheel 24 and the other ends abutting Ythe retaining disk 39. Said disk 39 and springs 43 are not included in Figure 5, being omitted for the sake of clearness. 1

Thethimble-cam 42 may be slidable along the platen-shaft 12 and its'periphery may be formedso as to spread the levers 34 when said thimble is pushed inwardly between the arms 36 of said levers, as seen in Figure 4,- and conversely to release saidlevers when said thimble-cam v42 is pushed outwardly to the position seen in Figure l. In order that the thimble-cam 42, which is betweentheend of the platen and left end member 10 ofthe platen-frame, may be operated from a point `outside said platen-frame to release or engage the platen-clutch, means are provided Awhich include a `finger-knob 44l slidable along the platen-shaft 12. r Projecting from the inner face of said knob are a pair of pins 45 on opposite sides of the platen-shaft, said pins passing through the platen-frame end `member 10, and also through a block 46 Which `may be secured to said end member 10by a screw 47v and adowel 49. The pins 45 .mayhave a sliding-fit inthe end;member 10- and the block 46. For connecting the thimble-cam 42 with lthe pins 45 soA that movement of the finger-knob 44 along` the platen-shaft 12 will effect a corresponding movement "of said thimble-.cam 42 to release vor engage the platen-clutch, the thimble-cam has a flange 50 having formed therein an annular groove 5 1.- Said groove eml braces heads 52 formed on the 'pinsf45 by grooves 53, the` outer side of the thimble-cam groove 51 overlapping the inner side of said heads 52 of the pins 45. Assembly of 'the thimble-'cam42 ,Y

over said heads 52v ofthe pins 'may be effected, as indicated in Figure 6, by springing or bending the pins 45. lAn alternative Way of'assembhng said thimble-cam 42 over the pins 45 is to first assemble said pins Within the groove 51, `then to thrust said pins through the end member 10 and block 46, and finally to assemble the finger-- knob 44 over the outer ends of the pins, said pins4 being then secured to said finger-knob .44 in any suitable way, as, forV example, by riveting over their outer ends 55. n

For adjusting the force with which the arcuate'clutch-members 30v grip the 'annular surface of the shell 19, the ends of` said members which abut the block 31 are spread more or lessfby ,expansion or contraction of the block itself.

The block has, therefore, av kerf 56 bisecting, a hole,` into which a taper-screw 57 is threaded. Due to the taper of saidscrew, the'block will be more or less expanded, depending on how far the screw is entered into the hole. For locking thescrew 57, a transverse screw 58 is provided,1 said screw passing through a tongue 59 projecting beyond thev clutch-members 30, 1e-`V vers 34 and the retaining plate 39, as seen in Figures l1 and 4. The 'withdrawal of the thimble-cam 42, to` unlock ythe platen, may be` limited by itsabutmentwith a hub 60, which mayV .be formed integral withV the platen-frame end member 10, as seen in Figure 1. Inwardmove- -ment of the thimble-cam 42, forlocking the linespace .'wheeland platen together, may be limited by abutment of the ange 50 ofsaid cam with the outerface of the line-space wheel24,V as seen in Figure 4. In moving 4the thimble-cam inwardly, the ends or heads ofthe pins 45 push againstl the bottom ofy the depression within Whose annular edge. the groove 51 is formed.

.When the thimble-cam has 'been pushed in to,

pressed into grooves 63 of the vpins 45, each ball L I" 62 being pressed against `its pin by a spring 64` backed up by a screw 65. As indicated in Fig-v ures 1 and 4, 'the balls 62, springs 64 and :screws 65 are contained in the aforementioned block I 46 that issecured to the outerside of the platen "MU frame end member 10.V The block 46 may have holes 66 arranged as shown in Figure. 8, into Which the steel detent-balls 62 are first inserted and depress springs 64, theouter ends of said holes having a threaded portion 69 forrthe 1 screws 65. For preventing the line-space wheel 24 and its attached clutch-parts from creeping outwardly from the shell 19, there mayr extend inwardly from the platen-frame end member. 10 a suitable projection or stud 67as indicated in Figure 1. l

Withdrawal of the entire platen is easily effected when the platen-shaft 12 is Withdrawn. Said shaft may be Withdrawn when the setscrew 16-is loosened. A slight cocking of the platen when they shaft is withdrawn will bring its end clear of the vhub 61 of the right platenframe end member 11, after which the entire platen may be withdrawn without hindrance.A

Conducing to ease of platen-withdrawal is a sufficient enlargement of the. hole 68, whereby the line-space wheel 24 clears the thimble-cam 42.

Also conducing to ease ofr withdrawal of the platen is the'capability which the thimble-cam 42 has of floating about its pointsof attachment with the pins 45' when the platen-shaftl 12 has been withdrawn. Withdrawal of the platen being thus easily effected,v it may withsimilar ease be put back into the platen-frame again, where` upon the platen-shaft 12 maybe easily inserted and the set-screw 16 tightened.- In withdrawing the platen from the typewriter, it is moved upwardly and forwardly, and, in order that the thimble-cam may Yfloat in a corresponding di- `rection when the platen is withdrawn, the pins 45 are placed along an oblique line, as indicated in Figures 5 and 7. For the same reason, the

stud 67 may also be placed on or below said line.

Co-operating with the line-space wheel 24, for holding the platen in line-space positions, is the usual spring-pressed detent-arm 7G, which Vengages notches 71 inithe rim of the line-spaceA wheel.

It will be noted that the platen-journals are no larger than the platen-axle 12 itself, thus conducing to free rotation of the platen, which enables the spring-pressed line-space detent-arm and roll to accurately locate the platen by means of the line-space wheel detent-'notches '71. After the thimble-cam 42 has, bymeans of the pins 45, been pushed in until it abuts the line-space wheel 24, the detent 62 may cause a slight retraction of said pins 45, so that theV nism organization is the shortening of the core l4tand the enlargement of its central opening, so that the shell 19 andits hub 20 may be receivedV in the end of the platen. There is no weakening of the core-structure to preclude the use of the usual wooden core. When the platen is withdrawn from the typewriter, it is to all appearances like the regular portable typewriterplaten, the line-space Wheel 24 being in the same position relatively to theend ofthe platen as in the regular platen, and, moreover, presenting the same flat left end of the platen. The opposite end of the platen has, as already mentioned, the regular hub 15.

Variations may be resorted to within the scope of the invention, and'portions of the improvements may be used without others.l

Having thus described my invention, 1 claim: 1. 'Ihe combination with aplaten-frame having ends, Va platen-shaftjournaled in and spanning said ends, a rotary platen keyed to said shaft l and located between the frame-ends, and a loosepass said frame inspaced relationship from theA shaft, so that theshaft itself is journaled directly in said frame-end.

2. A revoluble platen-assembly including a core somewhat shorter 'than the platen, so as to form in one end of the platen a shallow recess, a shell within said recess forming a continuation of said core and also forming an'annular surface, a loose disk at the inner end of said shell, having projections spaced fromvthe center of the disk and extending toward theouter end of said shell, a line-space ratchet-wheel mounted on said projections and forming a cover for said shell, said shell, disk and platen being arranged for rotation of said platen and its shell relatively to said wheel, a pair of diametrically opposite gripping members conforming to said annular shell-surface, said loose disk having a projection abuttingr one end of each of the gripping members, said membersforrning aV space at their other ends, and a pair offlevers having arms forming a toggle for spreading the spaced ends of said members to cause them to grip said surface, said leversV also having operating arms extending towardopposite sides of thevplaten-axis, said gripping members and levers arranged in a common plane against said disk, said line-space Wheel having a central Opening for .the insertion `of means for spreading said operating arms.

3. In a portable typewriter, the combination with a platen-frame having ends, a rotary platen,

and a one-piece platen-shaft journaled in said ends, of a looseline-space wheelgbetween one end of the platen and the platen-frame-end clutchmechanism between said'wheel and the end of the platen for releasably locking said platen and wheel together, a thimble-carn slidable along said shaft for actuating said clutch-mechanism, and located between the endl of the platen and theplaten-frame-end, a finger-knob slidable on said shaft outside of the platen-frame-end, pins passing said platen-frame-end, and connecting said and detent-devices knob and thimble-cam, mounted on said frame-end and effective for detenting said cam when the platen and line-space wheel are locked together. v

4. In a portable typewriter, the combination' with a platen-frame having ends, a rotary platen, and a one-piece platen-shaft journaled in said mechanism between said wheel and the end of ends, of a loose line-space wheel between one end of the platen and the platen-frame-end, clutchwheel together, a thimble-cam slidable alongsaid shaft for actuating said clutch-mechanism, and

located between the end of the platen and the platen-frame-end, a finger-knob slidable on-said shaft outside of the platen-frame-end, pins passing said platen-frame-end, and connecting said knob and Vthimble-cam, and spring-pressed de- `tents mounted in said frame-end and engaging and the platen-frame-end, a finger-knob slidable axially of said shaft outside of the platen-frameend, said cam having a flange forming a peripheral groove, and pins projecting inwardly from said knob and passing said platen-frame-end, said pins formed at their inner ends .for articulation with said groove in a manner to permit rotation of said cam when said cam is interlocked with said clutch. Y

6. The combination with a rotary platen and a loose line-space wheel, of a shell fastened to and sunk into one end of said platen to form an annular bearing surface, a pair of arcuate clutchmembers for gripping said surface, a pair of levers having arms forming a toggle between spaced ends of said clutch-members, a loose disk within said shell, spaced from the outer end thereof and having a projection against which the other ends of said clutch-members abut, said projection having a kerf so that it may be more or less expanded toadjust the grip of said members, a wedgein said kerf for so adjusting said projection, and a transverse screw for drawing Vthe split portions of said projection together to lock said Wedge in adjusted position, said disk having other projections extending outwardly, and to which said linespace wheel is fastened to form a cover for said shell.

7. The combinations with a rotary platen and a loose line-space wheel, of a shell fastened to and sunk into one end of said platen to form an annular bearing surface, a pair of arcuate clutchmembers for gripping said surface, a pair of levers having arms forming a toggle between spaced ends of said clutch-members, a loosedisk within said shell, spaced from the outer end thereof and having a projection against which the other ends of said clutch-members abut, said projection having a kerf so that it may be more or less ex- Aplate within said shell for retaining said members and levers against said disk, said line-space wheel forming a coverrfor the outer end of Said shell,A

said disk having other projections to which said line-space wheel is fastened,

WALTER E'rri/rLLER.` 

